1. Technical Field
The present invention relates to an ink reservoir for an inkjet print head, and more particularly to an inkjet print head for regulating the internal pressure in its housing in order to reduce the amount of ink remaining and thereby enhance efficiency in ink storage.
2. Related Art
An inkjet print head includes a housing for storing ink, and an ink spraying device for spouting the ink contained in the housing when electric energy is applied thereto. The housing supplies ink by producing an internal pressure for offering ink to the ink spraying device. When the amount of ink in the housing decreases, an air bag expands proportionally. With the air bag increasing, the ink stored in the housing receives a predetermined pressure.
As a result of this pressure, the ink is supplied to the ink spraying device. The ink offered to the ink spraying device is spouted and prints when electric energy is applied. As such procedure is repeated, the ink supply becomes gradually exhausted as a result of ink being sent to the ink spraying device from the housing. Upon consumption of the ink, the air bag expands within a predetermined limit. The air bag is made to expand in proportion to the ink storage capacity of the housing. As a result, the pressure generated by the air bag has a limit so that a predetermined amount of ink is left in the housing. For this reason, there is required an inkjet print head for regulating the internal pressure in the housing to thereby reduce the amount of ink remaining after exhaustion or full consumption of the ink supply.
The following patents are considered to be representative of the prior art relative to this invention, but are burdened by the disadvantages discussed herein: U.S. Pat. No. 5,709,253 to Maerzke entitled a Method For Refilling An Inkjet Cartridge And Apparatus To Modify A Cartridge With A Negative Pressure Reservoir, U.S. Pat. No. 5,686,947 to Murray et al. entitled an Ink Jet Printer Incorporating High Volume Ink Reservoirs, U.S. Pat. No.5,684,521 to Salter et al. entitled a Compact Fluid Coupler For Thermal Inkjet Printer Cartridge Ink Reservoir, U.S. Pat. No. 5,663,753 to Story et al entitled a Recording Cartridge With Replaceable Liquid-Containing Reservoir, U.S. Pat. No. 5,650,811 to Seccombe et al. entitled an Apparatus For Providing Ink To A Printhead, U.S. Pat. No. 5,646,666 to Cowger et al. entitled a Back Pressure Control In Ink-Jet Printing, U.S. Pat. No. 5,590,510 to Mochizuki et al entitled an Ink-Jet Recording Apparatus And Ink Tank Cartridge Thereof, U.S. Pat. No. 5,486,855 to Carlotta et al entitled an Apparatus For Supplying Ink To An Ink Jet Printer, U.S. Pat. No. 5,464,578 to Salteretal. entitled a Method Of making A Compact Fluid Coupler For Thermal Inkjet Print Cartridge Ink Reservoir, U.S. Pat. No. 5,459,497 to Manning et al. entitled an Ink Supply System For Continuous Ink Jet Printer, U.S. Pat. No. 5,450,112 to Scheffelin entitled a Laminated Film For Ink Reservoir, U.S. Pat. No. 5,440,333 to Sykora et al. entitled a Collapsible Ink Reservoir And Ink-Jet Cartridge With Protective Bounding Layer For The Pressure Regulator, U.S. Pat. No. 5,420,635 to Dietl et al entitled an Ink Supply System For A Thermal Ink-Jet Printer, U.S. Pat. No. 5,278,584 to Keefe et al. entitled an Ink Delivery System For An Inkjet Printhead, U.S. Pat. No. 5,233,369 to Carlotta et al. entitled a Method And Apparatus For Supplying Ink To An Ink Jet Printer, U.S. Pat. No. 5,223,860 to Loofbourow et al. entitled an Apparatus For Supplying Phase Change Ink To An Ink Jet Printer, U.S. Pat. No. 5,121,132 to Pan et al. entitled an Ink Delivery System For Printers, U.S. Pat. No. 4,937,598 to Hine et al. entitled an Ink Supply System For An Ink Jet Head, U.S. Pat. No. 4,929,963 to Balazar entitled an Ink Delivery System For Inkjet Printer, U.S. Pat. No. 4.914,453 to Kanayama et al. entitled an Ink Reservoir Of Ink Jet Printer, U.S. Pat. No. 4,899,178 to Tellier entitled a Thermal Ink Jet Printhead With Internally Fed Ink Reservoir, U.S. Pat. No. 4,824,487 to Heffernan entitled a Cleaning Of Polyurethane Foam Reservoir, U.S. Pat. No. 4,424,521 to Lewis et al. entitled an Ink Jet Apparatus And Reservoir, U.S. Pat. No. 4,119,034 to Wax entitled a Leakproof ink Supply Reservoir, U.S. Pat. No. 4,025,928 to Hou et al. entitled a Unitary Inkjet And Reservoir, U.S. Pat. No. 4,791,439 to Guiles entitled an Ink Jet Apparatus With Improved Reservoir System For Handling Hot Melt Ink, U.S. Pat. No. 4,739,347 to Ishikawa et al. entitled an Ink Supply System For Use In An Ink-Jet Printer, U.S. Pat. No. 4,580,147 to Deyoung et al. entitled an Ink Jet Apparatus With Imprived Reservoir System For Handling Hot Melt Ink, U.S. Pat. No. 4,513,297 to Okamura entitled an Ink Jet Printer Reservoir, U.S. Pat. No. 4,511,906 to Hara entitled an Ink Liquid Reservoir In An Ink Jet System Printer, and U.S. Pat. No. 4,509,062 to Low et al. entitled an Ink Reservoir With Essentially Constant Negative Back Pressure.